Warring States Period

The Warring States Period occurred from 475 to 221 BC as Zhou China was divided into several warring kingdoms which vied for supremacy. While the Zhou emperor was the de jure ruler of China, real power rested with the kings of the seven warring states, and the land was in perpetual war until King Ying Zheng of Qin conquered Chu in 223 BC and founded the Qin dynasty as "Qin Shi Huangdi".

Background
The beginnings of warfare in ancient China saw peasant soldiers armed with bronze or stone weapons under the command of aristocratic warriors in chariots. The first dynasty in China was the Shang, ruling around the Yellow River valley from 1600 to 1050 BC. The Shang was succeeded by the Zhou, which introduced the use of iron weapons. The Zhou supported a substantial standing army that campaigned against the "barbarians" around the borders of the realm. The Zhou dynasty officially lasted until 256 BC, but in reality central authority disintegrated in the course of the 8th century BC, initiating a long and complex period of wars between competing Chinese states. This is known as the Spring and Autumn Period. Beginning around 770 BC, it was a long prelude to the Warring States Period, the start date of which historians conventionally give as 475 BCE.

History
The rulers of the Zhou dynasty created a feudal system in which power was devolved to regional lords, who depended on the allegiance of their own vassals controlling smaller areas. Conﬂict was inevitable in such an unstable system. In the Spring and Autumn Period the southerly state of Chu, centered on the Yangtze River, emerged as one of the most powerful players, competing with Yellow River states that included Jin, Qi, and Qin. There were many conﬂicts within and between these loosely structured states. Battles involved the offensive use of chariots - which in earlier times were probably employed only as mobile command platforms. The chariots were sometimes massed in large formations, with Jin reportedly ﬁelding 700 of them in the defeat of Chu at Chengpu in 632 BC. But armies can rarely have been large, given the limited resources of the fragmented feudal territories.

Massive state armies
The Warring States Period proper emerged through the reorganization and consolidation of the larger Chinese states - inevitably a gradual process. Jin, probably the most powerful state by 475 BC, broke up into three: Han, Zhao, and Wei. The four other states that eventually dominated the contest for power in China were Chu, Yan, Qi, and Qin. These seven states developed increasingly efﬁcient central administrations that could conscript hundreds of thousands of peasant infantrymen and equip them with mass-produced iron weapons. Heavy siege crossbows came into widespread use, as did small crossbows carried by skirmishing infantrymen pushed out in front of the line of battle. Chariots were still used - crewed by three men and pulled by four horses - but cavalry took over as a shock force. The Chinese learned about mounted warfare from ﬁghting the nomads on their frontiers. Wuling, ruler of Zhao, created the ﬁrst fully-ﬂedged Chinese cavalry around 300 BC, ordering his elite soldiers to abandon traditional robes for trousers. He used both mounted archers and heavy cavalry. But the core of any Chinese army was still the conscript peasant infantry, mostly armored for ﬁghting in close formation with long halberds and pikes.

The Art of War
Constant warfare in China led to the sophisticated discussion of strategy and tactics. This was the period when the great military thinker known as Sun Tzu wrote his famous work, The Art of War. Written around 400 BC, it is generally considered to be the world’s ﬁrst treatise on the theory and practice of warfare. In it he recommends the use of deception, and avoiding battle on the enemy’s terms. He also stresses the importance of intelligence, and highlights the impact of morale on the outcome of conﬂict. Sun Tzu’s theories were successfully put into practice by the Qi general, Sun Bin, when he defeated the superior forces of Wei, ﬁrst at Guiling in 354 BC, then again at Maling in 342 BC. On each occasion, remarkably, Sun Bin relieved the enemy's pressure on an ally not by marching to confront the Wei army directly, but by making a feinting move toward the Wei capital. When the Wei army then of necessity moved to defend its capital, Sun Bin succeeded in luring it onto terrain where it could then be surrounded and destroyed by his own waiting forces. Despite such tactical subtleties, victory in the great Chinese power struggle eventually went to the state that could mobilize the maximum resources for warfare - men, weapons, food, and other supplies - with the greatest efﬁciency. The victor in this early version of total war was Qin.

The mighty Qin
A state in western China, Qin underwent political and social reforms that, by the 3rd century BC, gave it a powerful centralized government that had crushed the residual independence of the old feudal aristocracy. Government ofﬁcials and military commanders were appointed on merit, and the population was mobilized for public works and war. Being close to the nomadic horsemen of the north, Qin also had access to a supply of good horses, a crucial edge as cavalry grew in importance. Through the ﬁrst half of the 3rd century BC, Qin's aggression forced the other states to form alliances and mobilize their own resources. Zhao, for example, conscripted all men over the age of 15. There were epic battles, as at Changping in 260 BC, where a Zhao army was encircled and massacred in a long encounter that may have involved a million men. Under the rule of King Ying Zheng from 246 BC, Qin crushed all its enemies, although the campaigns against the Chu tested it to the limits. Finally, though, in 221 BC Ying Zheng declared himself the ﬁrst emperor of a uniﬁed China as Qin Shi Huangdi.

Aftermath
The establishment of the Qin dynasty ended the Warring States Period, but proved short-lived. However, China remained unified until 220 AD, under the Han dynasty. After the death of the first emperor, Qin Shi Huangdi, in 210 BC, China looked set to return to the civil conflict of the Warring States Period. The successor to the throne, Qin Er Shi, was weak and incompetent, and rebellions soon broke out. A serious bid for power was made by Xiang Yu of Chu, who was contested by Liu Bang, a general controlling Han. Liu Bang won the contest and, as Emperor Gaowu, founded the Han dynasty, reconsolidating imperial authority in China: a state of affairs that would last another 400 or so years. The Han empire established by Gao was threatened by the Xiongnu, nomadic horsemen who were based in the northern steppes. To keep the horsemen out, the Han reinforced the Great Wall that Emperor Qin had built. Moreover, Han armies were sent through the wall to attack the horsemen in their home territory in an attempt to defeat them before they could get anywhere near the Great Wall. The combined measures succeeded, the Xiongnu were beaten, and eventually the horsemen were reduced to mere tributary status. Under the leadership of Emperor Wu (141-87 BC), marauding Han armies penetrated south as far as the Mekong River in Vietnam, west into Central Asia, and into northern Korea.